Electric-current regulator



(No Model.)

0. D. SIGSBEE, T. S. HAYWARD & F. S. ANDERSON.

BLEGTRIG CURRENT REGULATOR,

No. 477,708. Patented June 28, 1892.

UNITED STATES PATENT OFFICE,

CHARLES DVIGHT SIGSBEE, OF THE UNITED STATES NAVY, AND THOMAS S.HAY\VARD AND FRANK S. ANDERSON, OF'EASTON, MARYLAND.

ELECTRIC-CURRENT REGULATOR.

SPECIFICATION forming part of Letters Patent No. 477,708, dated June 28,1892.

Application filed September 11, 1891. Serial No. 405,435. (No model.)

To aZZ whom it may concern:

Be it known that we, CHARLES DWIGHT SIGSBEE, of the United States Navy,residing at Washington, District of Columbia, and

THOMAS S. HAYWARD and FRANK S. ANDER- SON, residing at Easton, in thecounty of Talbot and State of Maryland, have invented certain new anduseful Improvements inElectric-Ourrent Regulators or Rheostats; an d wedo here- [0 by declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

Our invention relates to electrical regulators or rheostats, and has forits object to provide for electric currents a resistance that may begreatly varied in power while varying only slightly or not at all themass and volume of the elements forming the resist- 2o ance device.

It has for its further object to provide a resistance device adapted towithstand a high degree of heat.

Our regulator consists of a cell or barrel of well-known utility,preferably closed at one end, excepting a channel through the wall toadmit the circuit or connections for the same, and open at the otherend, said cell being a nonconductive receptaclefor the elements com- 0posing our resistance device or combination and for contact-plates atthe extremities of said device or combination. It also serves as asupport for the means that we employ for varying the pressure upon ourresistance de- 5 vice.

Our resistance device is composed of material of a moderate degree ofconductivity, arranged in alternate layers, with regulating pieces orplates of a lower degree of conduc- 0 tivity or no conductivity, saidregulatingplates being perforated in a manner to limit the flow ofcurrent through or past the plates and to direct the current in thedesired route, devious or otherwise, through the more con- 5 ductivematerial inclosed between the regulating-plates. The perforations inadjacent plates may be so arranged that by merely readjusting saidplates, without otherwise altering the elements of our resistancedevice, the route of the current may be lengthened or shortened and thepower of the resistance as originally established thus increased ordiminished, as will be shown.

It is obvious that the longer the route of the current the greater willbe the resistance also the greater the area of the perforations in theregulating-plates the greater the amount of current passing through theresistance device. Finally, having established the initial resistance ofthe mass of our resistance device the resistance as thus established maybe varied by varying the pressure upon the mass, a well-known principlewhich we put into execution by means of a compressorserew, theconductivity of the mass incrcasing with the pressure.

The regulator is placed in the circuit of an electric lamp, machine, orapparatus to which the current is supplied from any generator, and thecircuit maybe supplied with any suitable switch or circuit-breaker, orboth.

e may use our resistance device as described herein in lieu of theresistance substance set forth in our patent for an electriccurrentregulator or rheostat, No. 454,965), 5 dated June 30,1801, using any orall of the mechanical details set forth in that patent; but havingclaimed said details in said patent, they are not claimed herein.

Referring to the accompanying drawings, Figure 1 is a front view of theoutside of our regulator. Fig. 2 is a vertical section of the regulatoron the line a Z") of Fig. 1. Fig. 3 shows a series of pieces or platessuch as are contained in the cell of Fig. 2, and shown 8 therein insection. Fig. 4 shows a pair of adjacent regulating plates perforated ina slightly-different manner from those shown in Figs. 2 and Fig. 5illustrates a pair of adjacentregulating-plates,one being assumed to bebehind the other, with conductive ma terial between the two, theperforations of the front plate being shown in full line and those ofthe rear plate in dotted line. Figs.

6 and 7 are continuations of Fig. 5, and show 5 the same pair ofregulating-plates rearranged in successive stages to lengthen the routeof the electric current through the successive perforationsi. 6.,through the resistance device. Figs. 8 and 9 show a modification in I00which two regulating-plates are in contact, the two forming practicallyone plate. The perforations of the said plates being made to overlapeach other more or less, the area of the common aperture is therebyincreased or diminished. Figs. 10 and 11 are 1nodifications of Fig. 2,which will be explained here inafter.

Like letters of reference in the several figures denote the same parts.

To carry into execution our invention, we have the non-conductor cell A,open at one end and closed at the other, as shown, and provided with thechannel :1; to admit the electrical wiring or connections. Vithin thecell are the metallic contact-plates B and B and the metallicpresserplate 13*. Included between the contact-plates are layers ofconductive material C O C 0 &c., alternating with regulating-plates D DD D &c., the said layers and plates constituting what we style ourresistance device-i. 6., our resistance device proper. Theregulating-plates are perforated with holes of any suitable size andshape and in any suitable positions in said plates, and are fittedneatly to the chamber of the cell, but adapted to free movement therein.

In Fig. 2, which repeats in section the contactplates,regulating-plates, and perforations shown in Fig. 3, the course of thecurrent through the resistance device in this arrangement ofperforations exhibited is clearly shown by means of arrows passingthrough the perforations p p, &c.

In order to vary the conductivity of our conductive layers 0 OC ,&c.,byvaryingthe pressure thereon, we have provided the compressor-screw E,working in the bearing-plate or bridge F, which is seated in the wall ofthe cell. Contacts with the circuit are made at the contact-plate B andthe bearing-plate F, the circuit-wires or connections being shown at Gand G. The contact of G maybe made on the compressor-screw, as g, or onthe contact-plate B, as g g, if desired. It should be understood thatthe adjacent layers of conductive material C G 0 &e., are so formed ordisposed as to have mutual contact or continuity through theperforations of their corresponding regulating-plate, although in Fig. 2the perforations are left white for clearness of illustration as awhole.

Our conductive layers may be formed of any suitable material 3 but weprefer that they shall be of moderate conductivity only, yet of a higherconductivity than the regulatingplate. Our purpose is best secured by amaterial having considerable elasticity under pressure, in order that awide range of compressor action may be secured. lVhile asolid or fibroussubstance or material may be used for this purpose, we prefer acomminuted or powdered substance, as powdered graphite or other carbons,or powdered metals also, simple powders having the grains plated orcoated with a substance of higher or lower conductivity than the grainsthemselves. Powdered graphite has been found to give goodresults and hasa great capability to withstand heat.

Our perforated regulating-plates may be made of any suitable material oflow conductivity,or,practically, no conductivity; but we prefer mica forits compactness, non-conductive quality, stiffness, smooth surface, andcapability of withstanding heat.

To increase the range of compressor action and to prevent the escape orleakage of the conductive material C O C 0 &c., we use the elasticpacking-pad H, inclosed between the contact-plate B and thepressor-plate 13 as shown in Fig. 2, the chief office of thepresser-plate being to transmit pressures from the compressor to thepacking-padand the resistance device. The said pad is composed ofelastic fibrous material, as spun silk or cotton, but preferably ofasbestus or other fiber of non-conductive quality. lVe also employ themetallic spring conductor-piece J to conduct the current from thecontact-plate 13 of Fig. 2 to the compressor screw or presserplate. Vemay, however, make the pad H of fiber, coated or plated or polished withgraphite or other conductor to a degree that shall be highly conductive,in which case we dispense with the spring conductorpiece J. When we usea pad of this quality, we do not use it as a resistance, but as aconductor of high conductivity and as a packing.

In Fig. 10 is shown a modification of the position of the springconductor-piece J. This arrangement allows the pad to be more readil yinserted into the cell and adj ustedtherein.

We may also use our elastic packing-pad at the bottom of thecell-chamber, as shown in Fig. 11, which figure is a section through thebottom of the cell similar to Fig. 2, to prevent the leakage of powderor other conductive substance of ourresistance device through thechannel m of the cell, in which case we gain an additional range of ourcompressor action. We may also use one or more pads at intermediatepositions in our resistance device.

lVe do not confine ourselves to anyparticular arrangement ofperforations in our regulating-plates, nor to any particular sizes orshapes of the perforations, as our invention admits of manymodifications in these respects. For example, Fig. 4- shows a pair ofadjacent regulating-plates, one being perforated centrally and the otheralong its edge, an arrangement calculated to provide a very long routefor the current through our resistance device. Also in Figs. 5, 6, and 7we show how in a single regulating device we can alter the initial powerof resistance of said device without increasing or diminishing thematerials composing said device1l.e., by simply readjusting one or bothplates, so that their corresponding perforations shall have differentrelative positions. It is obvious that in Fig. 5 the resistance would beless than in Fig. 6, and in the latter less than in Fig. '7,

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an increase due in each case to lengthening the route of the current.Also, in Figs. 8 and 9 we show whatis practically one regulatingplate,but one composed of a double layer of the material or substance that weemploy for our regulating-plates. In said. figures one layer is assumedto be behind the-other, but both layers are in contact and no adjacentregulating-plates of either single or double structure are shown. Saidfigures show that by readjusting one or both of said layers composingthe double plate the common aperture may be increased or diminished inarea, and the current through the aperture correspondingly varied inamount.

In action and office the modified regulating-plate of Figs. 8 and 9 isthe same as the regulating-plate shown in other figures.

We do not limit ourselves to any particular number of regulating-platesthat We may employ in our resistance device. We may employ more or less,according to the special purpose to be secured. Even one may in somecases serve the purpose. We may also pro vide special mechanism forrotating our regulating-plates about their axes to obviate opening thecell and removingany of the contents. We may also place aregulating-plate in contact with one or both of the contact-plates B andB of Fig. 2 on the inner side of said contact-plate, or wemayplaceitsimilarlyin contact with the presser-plate B of Fig. 11.

Having thus described our invention, what we claim as new is- 1. Aresistance device or mass of compound structure for electric currents,composed of electric conductive material and one or more perforatedregulating-plates of lower conductivity, substantially as set forth.

2. A resistance device or mass of compound structure for electriccurrents, composed of electric conductive material arranged in alternatelayers with one or more perforated regulating-plates of lowerconductivity, sub stantially as set forth.

3. A resistance device or mass of compound structure for electriccurrents, composed of powdered graphite and one or moreregulating-plates of perforated mica, substantially as set forth.

4. A resistance device or mass of compound structure for electriccurrents, composed of powdered graphite arranged in alternate layerswith one or more regulating-plates of perforated mica, substantially asset forth.

5. In a rheostat, the resistance device or mass of compound structure,composed of electric conductive material and one or more perforatedregulating-plates of lower conductivity and in combination therewith thecontact-plates at the terminals of said structure, substantially as setforth.

6. In a rheostat, the resistance device or mass of compound structure,composed of I electric conductive material and one or more perforatedregulating-plates, together with the contact-plates at the terminals ofthe resistance device, in combination with the compressor-screw and thecell or receptacle,substantially as set forth.

7. In a rheostat, the combination, with the compressor, the cell, andthe resistance device or material contained in the cell, of one or moreelastic packing-pads and one or more resser-plates, substantially as setforth.

8. In a rheostat, the combination, with the compressor, the cell, andthe resistance device or material contained in the cell, of one or morepacking-pads of asbestus, and presserplates B and conductorpieces .I,substantially as set forth.

9. In a rheostat, the combination, with the compressor, the cell, thecontact-plates, and the resistance device or material contained in thecell, of one or more packing-pads of arbestus fiber carrying aconductive substance, and of one or more presser-plates, substantiallyas set forth.

10. In a rheostat, a perforated regulatingplate of low conductivity,substantially as set forth.

11. In a rheostat, a perforated regulatingplate of mica, substantiallyas set forth.

12. In a rheostat, a regulating-plate composed of two or more layers ofmaterial of low conductivity, perforated, relatively, in a mannerwhereby the common aperture or -apertures through said plates may bevaried in area by varying the relative positions of contact of saidplates, substantially as set forth.

13. In a rheostat, two or more regulatingplates perforated, relatively,in a manner to direct the electric current flowing through saidperforations in a more or less devious route through the conductivematerial of said rheostat, substantially as set forth.

In testimony whereof we affix our signatures in presence of witnesses.

CHARLES DW'IGHT SIGSBEE. THOMAS S. IIAYXVARD. FRANK S. ANDERSON.

Witnesses as to signature of Charles Dwight Sigsbee:

F. H. TYLER, Rrormnn RUsH. Witnesses as to signatures of Thomas S.Hayward and Frank S. Anderson;

I. O. HARDIN, JOHN SATTERFIELD.

